JPH0643842U - Tape recorder auto-reverse device - Google Patents

Abstract

(57) [Abstract] [Purpose] To make it possible to reliably switch the tape running direction in the tape recorder auto reverse device in a small space. [Construction] Running direction switching plate 1 for switching the running direction of the tape
The movement switching of 0 in the left and right direction is performed by the transmission gear 22 that half-rotates by meshing with the toothless gear 12 that is rotationally transmitted through the sliding rotation transmission mechanism, and at the end of the lateral movement of the traveling direction switching plate. By the reaction force acting on the traveling direction switching plate, the transmission gear is rotationally biased in the rotation continuing direction to hold the traveling direction switching plate at the movement end position.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an auto-reverse device for a tape recorder that reliably switches the tape running direction by switching the motor rotation direction in a small space.

[0002]

[Prior art]

 An automatic reversing device for a tape recorder that changes the running direction of the tape by changing the rotating direction of the motor is disclosed in Japanese Utility Model Publication No. 3-41295. It is composed of a mechanism and a holding mechanism that holds the traveling direction switching plate for operating the pinch roller switching mechanism at one or the other movement end position.

The pinch roller switching mechanism is formed on the traveling direction switching plate by moving the traveling direction switching plate to one side or the other, and the cam selectively rotates the support arm that supports the pinch roller to move the pinch roller. The roller is switched between the pressure contact state and the corresponding capstan. The traveling direction switching mechanism includes a Y-shaped swing lever connected to the traveling direction switching plate, cam gears provided at both ends of the swing lever, and a swing gear that rotates by switching the rotation direction of the motor. It is composed of and. Then, the swing gear revolves by switching the rotation direction of the motor, the swing gear selectively meshes with the cam gear to rotate the cam gear, and the rotation of the cam gear causes the cam to rotate the swing lever in a predetermined direction. The traveling direction switching plate is moved to one side or the other by rotating the swing lever.

The swing gear is always meshed with an intermediate gear that is rotationally transmitted from a motor, and when the rotation direction of the intermediate gear is switched by switching the rotation direction of the motor, a rotating plate that supports the swing gear is provided. At the same time, the outer periphery of the intermediate gear revolves in the same direction as the rotation direction of the intermediate gear. The turning force of the swing gear is generated by the rotational load of the swing gear itself. The rotating plate is supported coaxially with the rotation shaft of the intermediate gear so that the swing gear and the intermediate gear are constantly meshed with each other.

The holding mechanism is composed of a traveling direction switching plate, a substrate, and a reversing spring suspended between them. When the traveling direction switching plate is moved to a position beyond the fulcrum of the reaction spring by the rotation of the swing lever, the reversing spring causes the elastic force of the reversing spring to further move the traveling direction switching plate in the moving direction. , The traveling direction switching plate is held at the moving end position by the elastic force of the reversing spring.

[0006]

[Problems to be solved by the device]

 In the above auto reverse device, the swing gear is revolved in accordance with the rotation direction of the motor, and the moving direction of the traveling direction switching plate is switched using this. For this reason, a large space for revolving the swing gear is required, and there is the inconvenience that the arrangement of components on the board is restricted. Further, since the rotating plate is rotated by the rotation load of the swing gear itself, the turning force becomes extremely weak. For this reason, it is necessary to support the rotation of the rotating plate so as not to apply a rotational load. However, if the rotating load of the rotating plate is reduced, it will rotate when an external impact is applied to the tape recorder. There is a possibility that the plate may rotate to switch the running direction of the tape, which reduces the reliability of the device. Then, when lubricating oil is applied to the rotary plate in order to reduce the rotational load of the rotary plate, dust is adsorbed on the lubricating oil and the amount of this dust increases, resulting in an increase in load. Therefore, only a very limited amount of lubricating oil could be applied to a very limited place.

Further, since the reversing spring is used as the holding mechanism for holding the traveling direction switching plate at the position moved to one side or the other side, a space for rotating the reversing spring is required, and in order to secure this space, the space on the substrate is required. The parts layout was restricted. An object of the present invention is to provide an automatic reverse device for a tape recorder which is highly reliable and can change the running direction of the tape in a small space.

[0007]

[Means for Solving the Problems]

 A drive gear that rotates forward and backward in response to the torque of the motor on the substrate, and first and second toothless portions, and a toothed portion formed between the first and second toothless portions. Is engaged with the drive gear to rotate forward and reverse, and when the first and second toothless portions face the drive gear, the toothless gear that is prohibited from rotating in the rotational direction and the slip transmission from the motor are transmitted. Rotational force is transmitted through the mechanism, and a starting gear that rotates the toothless gear in the forward or reverse direction and an engaged portion that engages with the engaging portion of the traveling direction switching plate are provided. A transmission gear that meshes with the teeth and rotates half or slightly more by half rotation and moves the running direction switching member to one or the other depending on the direction of rotation, and the transmission gear at the end of rotation of this transmission gear. A blocking portion that abuts against the contact portion of the transmission gear to prohibit rotation of the transmission gear in the rotation continuation direction. It is characterized in. Further, the engaging portion of the traveling direction switching plate forms an inclined surface that biases the transmission gear to rotate in the direction in which the engaged portion abuts against the blocking portion at the left and right rotation ends of the transmission gear, and the transmission gear may be one or the other. It is characterized in that it is provided with an elastic member for urging the engaged portion in the direction of abutting against the blocking portion near the end of rotation.

[0008] Furthermore, it meshes with the partially toothed gear that rotates in the normal and reverse directions and rotates half or slightly less than half, and the arc movement of the engaged portion is transmitted to the traveling direction switching member. The direction switching member is moved to one side or the other, and when the traveling direction switching member is not driven, the transmission gear arranged to face the toothless portion of the toothless gear and at least the toothed portion of the toothless gear is transmitted. It is characterized in that pressing means for continuing to urge the transmission gear in the rotation continuing direction by receiving a reverse load acting on the traveling direction switching member from immediately before disengagement from the gear is provided.

[0009]

[Action]

 Transmission of moving the traveling direction switching plate by controlling the meshing of the toothless gear and the drive gear by switching the rotational direction of the starting gear that rotates the rotation of the motor through the slip rotation transmission mechanism. Drive the gear. Since each gear does not rotate, stable operation is achieved, and since it is axially supported by the substrate, a small space can be achieved. In addition, the transmission gear that moves the traveling direction switching plate is rotated halfway or slightly more than half the rotation, and the abutment part abuts the blocking part, preventing the transmission gear from rotating in the continuous rotation direction. Therefore, the reaction force of the traveling direction switching plate can rotate and bias the contact portion in the direction in which the contact portion abuts against the blocking portion, and the traveling direction switching plate can be held at the position moved to one side or the other side. Even if the rotation of the transmission gear is slightly less than the counter rotation, the transmission gear continues to rotate under the reverse load acting on the traveling direction switching member immediately before the transmission gear disengages from the toothed part of the toothless gear. By providing the pressing means that keeps urging in the direction, the traveling direction switching member can be held at the position moved to one side or the other side.

[0010]

【Example】

 A first embodiment of the present invention will be described with reference to FIGS. In the tape recorder of FIG. 1, a pair of capstans 3a and 3b, which are rotated in the same direction by a motor 2 on a substrate 1, are rotatably attached. Pinch rollers 4a and 4b are rotatably attached to the support arms 5a and 5b at positions corresponding to these capstans, respectively. Between the pair of capstans 3a and 3b, a head mounting plate 7 on which a magnetic head 6 is mounted is attached to the substrate 1 so as to be able to move back and forth. When the head mounting plate 7 moves forward and moves to a tape reproducing position, the magnetic head is moved. 6 is adapted to slide on a tape of a cassette (not shown) to reproduce a signal.

A traveling direction switching plate 10 is mounted on the substrate 1 so as to be movable left and right in a direction orthogonal to the moving direction of the head mounting plate 7. The traveling direction switching plate 10 is moved left and right by a traveling direction switching mechanism provided on the lower surface of the substrate 1 to switch the traveling direction of the tape, as will be described later. Further, the traveling direction switching plate 10 moves left and right to selectively actuate a rotation transmission mechanism (not shown) on the pair of reel shafts 8a and 8b rotatably mounted on the substrate. This rotation transmission mechanism rotates the reel shafts 8a, 8b on the side where the pinch rollers 4a, 4b and the capstans 3a, 3b are in pressure contact with each other at a position where the traveling direction switching plate 10 has moved leftward or rightward from the motor. Is transmitted selectively.

A pinch roller switching mechanism 12 that selectively presses the pinch rollers 4 a and 4 b to the corresponding capstans 3 a and 3 b is provided with a rotary plate 13 rotatably mounted on a head mounting plate 7, and It has a rod panel 14 supported by the rotating plate 13 so as to rotate together with the rotating plate 13, and a connecting portion 15 connected to the rotating plate 13, and is supported on the head mounting plate 7 in a movable manner. It is constituted by the moving plate 16. The moving plate 16 has one end connected to the traveling direction switching plate 10, and at the position where the traveling direction switching plate 10 has moved to the left or right, the connecting portion 15 of the moving plate 16 rotates correspondingly. The plate 13 is rotated to the left or right together with the bar spring 14. When the one end of the rod spring approaches the one capstan due to the rotation of the rod spring 14, it separates from the other capstan on the other end.

When the head mounting plate 7 is at the reproduction position, the tip of the bar spring 14 rotated by the movement of the traveling direction switching plate 10 in the direction close to the capstan rotates the support arm 15 to pinch it. The rollers are pressed against the corresponding capstans. FIG. 1 shows a state in which the right pinch roller 4b is in pressure contact with the right capstan 3b. When the traveling direction switching plate 10 moves to the left from the state of FIG. 1, the moving plate 16 connected to this also moves to the left, and the movement of the moving plate 16 causes the rotating plate 13 connected to the moving plate 13 to move. , Rotate clockwise on the head mounting plate 7. Then, the rod spring 14 also rotates together with the rotating plate 13 and the left rotating tip 14a rotates the support arm 5a counterclockwise, and the left pinch roller 4a is pressed against the capstan 3a.

On the other hand, the tip 14b of the right bar spring rotates the right support arm 5b counterclockwise to separate the right pinch roller 4b from the capstan 3b. On the other hand, when the rod spring 14 presses the pinch roller against the corresponding capstan, the reaction force of the pressure contact force is transmitted to the traveling direction switching plate 10 via the rotating plate 13 and the moving plate 16 to switch the traveling direction. The plate 10 acts in the direction opposite to the moving direction of the traveling direction switching plate. That is, in FIG. 1, the reaction force urges the traveling direction switching plate 10 to move to the left.

A traveling direction switching mechanism for moving the traveling direction switching plate 10 to the left and right is provided on the lower surface of the substrate as shown in FIG. FIG. 2 is an enlarged view of the periphery of the capstan 3b on the right side of FIG. 1, and shows the substrate 1 and the traveling direction switching plate 10 in phantom lines. The traveling direction switching plate 10 is provided with a guide hole 18 (engagement portion) into which a prism (non-engagement portion) 22a of the transmission gear 22 described later fits. The prism 22a fitted into the guide hole 18 pushes the side surface 18a of the guide hole 18 by the rotation of the transmission gear 22, and causes the traveling direction switching plate 10 to move to the left or right against the reaction force. Move it to the right. Further, in the guide hole 18, the corner of the prism 22a is pressed at the end where the traveling direction switching plate 10 is moved by the prism 22a so that the prism 22a ends the ends 1b and 1d of the arc hole 1a of the substrate 1 shown in FIG. An inclined surface 18b that is pressed against the (blocking portion) is formed.

On the lower surface of the substrate 1, a flywheel 19 attached to the capstan 3 a, a small gear 20 (driving gear) integrated with the flywheel 19, and a first toothless portion of the small gear 20. A toothless gear 21 facing the toothless gear 21a and a transmission gear 22 at a position facing the second toothless portion 21b of the toothless gear 21 are rotatably supported by the substrate 1. An endless belt for transmitting the rotation of the motor 2 is hung on the outer circumference of the flywheel 19, so that when the rotation direction of the motor 2 is switched, the rotation of the flywheel 19 is also switched according to the rotation direction of the motor. Has become.

On the capstan 3 b, a starting gear 23 having a diameter smaller than that of the small gear 20 is rotatably provided above the small gear 20. As shown in FIG. 3, the starting gear 23 has a shaft hole 23a divided into two parts, and the shaft hole 23a is expanded by the diameter of the capstan 3b and press-fitted into the capstan 3b. There is. This press-fitting can be performed with an extremely weak force, and the fitting force between the shaft hole 23a and the capstan 3b is extremely weak.

The starting gear 23 rotates following the rotation of the capstan 3b due to the fitting force and the viscosity of the lubricant applied to the shaft hole 23a, and stops when an excessive load is applied to the starting gear 23. As a result, slippage is caused between the inner circumference of the shaft hole 23a and the outer circumference of the capstan 3b.

As shown in FIG. 3, the tooth-chipped gear 21 has a large-diameter gear 21c that constantly meshes with the starting gear 23, and first and second tooth-chipped portions 21a, 21b having a smaller diameter than the large-diameter gear 21c. A toothed portion 21d formed between the two is integrally formed with a circular arc groove 21e into which a stopper 1c provided on the lower surface of the substrate 1 is fitted. Note that, in FIG. 3, the large-diameter gear 21c and the toothed portion 21d of the partly tooth-missing gear 21 are shown in a state of being cut and separated in order to clarify the engagement with other gears. The circular arc angle of the circular arc groove 21e is such that when the first and second toothless portions 21a and 21b face the small gear 20, the stopper 1c abuts the terminal ends 21k and 21m of the circular arc groove.

The shaft hole 21f of the tooth-chipped gear 21 has two holes so that when it is mounted on the support shaft 1e provided on the substrate 1, the shaft hole 21f is spread by the support shaft 1e and is fitted into the groove 1f of the support shaft 1e. Is divided into The outer wall of the bearing portion 21g forming the shaft hole 21f and the toothless gear 21 are connected by an elastically displaceable arm 21h facing the toothless portions 21a and 21b in parallel. . A space 21j is formed between the bearing 21g and the arm 21h and the toothless gear 21. When the first tooth tip of the toothed portion 21d comes into contact with the tooth tip of the small gear 20 when the toothed portion 21d starts meshing with the small gear 20, the rotational force of the small gear 20 is reduced. By elastically displacing the arm 21h, the partly tooth-missing gear 21 can be moved in the radial direction and the state where the tooth tips are in contact can be avoided.

When the transmission gear 22 is attached to the substrate 1, the transmission gear 22 is inserted through the arc hole 1 a opened in the substrate 1 and protrudes to the upper surface side of the substrate 1 so that the traveling direction switching plate 10 is provided. A prism 22a fitted into the guide hole 18 is provided at an eccentric position. The circular arc angle of the circular arc hole 1a of the substrate 1 is a square column when the transmission gear 22 meshes with the toothed portion 21d of the toothless gear 21 and rotates slightly more than half a rotation due to the rotation of the toothless gear 21. The size of 22a abuts on the ends 1b and 1d of the arc hole 1a. Further, as shown in FIG. 4 viewed from the opposite direction, when the transmission gear 22 rotates on the lower surface of the substrate 1 to move the traveling direction switching plate 10 left or right, the rotation of the transmission gear 22 is reduced. A tension spring 24 is provided at the terminal end to bias the transmission gear 22 in the rotational direction.

The elastic force of the tension spring 24 presses the projection 22 b provided at the eccentric position of the transmission gear 22 by the tension spring 24, and thus pushes the transmission gear 22 toward both ends in the rotational direction. The elastic force of the tension spring 24 gives an auxiliary force for holding the transmission gear 22 at the rotation end position more reliably.

When the traveling direction switching plate 10 is moved to the right as shown in FIG. 2, the prism 22 a is a track that indicates the movement of the traveling direction switching plate 10 that passes through the rotation axis of the transmission gear 22. It is in a position rotated slightly beyond line 25. The prism 22a is in contact with the end 1b of the arc hole 1a of the substrate 1 at this position. Therefore, the transmission gear 22 is composed of the component force of the reaction force of the rod spring 14 acting on the traveling direction switching plate 10 acting through the inclined surface 18b of the guide hole 18 and the spring force of the tension spring 24. Is pressed against the end 1b of the arc hole 1a, so that it is reliably held at the end position in the rotational direction. Then, since the transmission gear 22 is held at the rotational end position, the traveling direction switching plate 10 is also held at the position moved to the right.

The operation of the auto reverse device of the first embodiment will be described. In the state of FIG. 1, the right pinch roller 4b is pressed against the capstan 3b, and the capstan 3b is rotated counterclockwise by the motor 2 to feed the tape from left to right. The sent tape is wound by the reel shaft 8b on the right side. At this time, as shown in FIG. 2, the toothless gear 21 is a starting gear 23 that rotates counterclockwise, and a large-diameter gear 21c that meshes with the starting gear 23 is given a rotational urging force in the clockwise direction. The toothless gear 21 is prevented from rotating in a state in which the one end 21k of the arcuate groove 21e abuts the stopper 1c by this rotational biasing force and the first toothless portion 21a faces the small gear 20. This rotational biasing force is a frictional force generated by the bearing 23a of the starting gear 23 sliding on the outer periphery of the capstan 3a.

The transmission gear 22 facing the second toothless portion 21b of the toothless gear 21 moves the traveling direction switching plate 10 to the right. Therefore, the reaction force of the rod spring 14 urges the traveling direction switching plate 10 to move to the left, and the urging force pushes the prism 22a counterclockwise via the inclined surface 18b of the guide hole 18. . In the transmission gear 22, a prism 22a is pressed against the terminal end 1b of the arc hole 1a of the substrate 1 by this rotational biasing force, and is also rotationally biased toward the terminal end by the spring force of the tension spring 24. Therefore, the transmission gear 22 is held in a state of facing the second tooth-chipped portion 21b of the tooth-chipped gear 21, and also holds the traveling direction switching plate 10 in a state of being moved to the right.

When the operation for switching the traveling direction is performed in this state, the rotation direction of the motor 2 is immediately switched. Then, the rotation directions of the flywheel 19, the capstan 3b, the small gear 20, and the starting gear 23 are switched, and the starting gear 23 rotates clockwise in FIG. Then, the rotational biasing direction of the tooth-chipped gear 21 by the starting gear 23 is switched, the tooth-chipped gear 21 is rotated and biased counterclockwise to rotate, and the toothed portion 21 d meshes with the small gear 20. . When the partly tooth-missing gear 21 starts to rotate counterclockwise by the rotational force of the small gear 20, the transmission gear 22 facing the second partly toothless part 21d also meshes with the toothed part 21d, thereby rotating clockwise. Start.

When the transmission gear 22 starts rotating clockwise, the prism 22a pushes the side surface 18a of the guide hole 18 while moving inside the guide hole 18 to move the traveling direction switching plate 10 leftward. The toothed portion 21b of the tooth-chipped gear 21 faces the transmission gear 22 with the first tooth-chipped portion 21a at a position where the transmission gear 22 is rotated slightly more than half a turn. On the other hand, at this time, the second toothless portion 21b faces the small gear 20, and the other end 21m of the arc groove 21e of the toothless gear 21 comes into contact with the stopper 1c, so that the small gear of the toothless gear 21. The rotation by 20 stops. However, as the starting gear 23 continues to rotate in the clockwise direction, the large-diameter gear 21c is given a counterclockwise rotational force, and the second toothless portion 21b faces the small gear 20 so that the starting gear 23 faces. It is held by the rotational force of.

The traveling direction switching plate 10 transferred to the left by the clockwise rotation of the transmission gear 22 moves the moving plate 16 to the left, so that the connecting portion 15 rotates the rotating plate 13 in the clockwise direction. To move. By this rotation of the rotating plate 13, the rod spring 14 rotates the left support arm 5a counterclockwise to press the left pinch roller 4a against the left capstan 3a, and the tape to the left side. Send in the direction. On the other hand, the rod spring 14 rotates the right support arm 5b counterclockwise to separate the right pinch roller 4b from the right capstan 3b.

Further, the traveling direction switching plate 10 operates the rotation transmission switching mechanism while moving to the left. The rotation transmission switching mechanism transmits the rotation of the motor 2 to the left reel shaft 8a and winds the tape fed from the left pinch roller 4a and the capstan 3a. Further, transmission of rotation from the motor 2 to the right reel shaft 8b is cut off.

As described above, the tape recorder auto-reverse device of the present invention switches the running direction switching plate 10 to one by switching the rotation direction of the motor 2 and switching the rotation directions of the toothless gear 21 and the transmission gear 22. Alternatively, the tape can be moved to the other to switch the running direction of the tape to the right or left direction. When the left pinch roller 4a is pressed against the left capstan 3a, the reaction force of the rod bar 14 urges the traveling direction switching plate 10 to move to the right. This moving biasing force presses the prism 22a so that the inclined surface 18b formed in the guide hole 18 of the traveling direction switching plate 10 rotates the transmission gear 22 clockwise. The prism 22a of the transmission gear 22 abuts on the other end side 1d of the arc hole 1a of the substrate 1 to hold the transmission gear 22 in a position in which the transmission gear 22 is rotationally biased in the clockwise direction.

As described above, in the first embodiment, when the tape traveling direction is switched by switching the rotation direction of the motor 2, the rotation direction of the motor 2 is switched by using the gear rotatably supported by the substrate 1. Since the direction of travel is switched, it is not necessary to rotate the gears, so space can be reduced. Further, the holding mechanism for holding the traveling direction switching plate 10 at the position moved to one side or the other side is provided with the inclined surface 18b of the guide hole 18 and the transmission gear 22 at a position where the rotation of the transmission gear 22 is slightly more than half a rotation. Since the blocking portions 1b and 1d for prohibiting the continuous rotation of 22 and the tension spring 24 for urging the transmission gear 22 to rotate in the continuous rotation direction are provided, the holding mechanism can be made small in space. Furthermore, since it is not necessary to rotate each gear, it is possible to stabilize the switching operation of the traveling direction.

In the above embodiment, the blocking portions 1b and 1d for blocking the half rotation of the transmission gear 22 are the both ends of the circular arc hole 1a provided in the substrate, but the invention is not limited to this. For example, as shown in FIG. 5 as a second embodiment, a concave portion 31b is formed in an edge portion 31a where the prism 22a is slidably contacted with the guide hole 31 of the traveling direction switching plate 30, and one surface of this concave portion is used as a blocking portion 31c. Alternatively, the other surface 31d may be a surface that presses the transmission gear in the rotation direction. When the center of the recess 31b is arranged so as to pass through the rotation center of the transmission gear 22, the traveling direction switching plate 10 allows the prism 22a to engage with the recess 31b even if the rotation of the transmission gear 22 is a half rotation. Thus, it can be held at the movement end position. Although the engaged portion is described as a prism, it may be a cylinder.

A third embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same members as those in the first embodiment are designated by the same reference numerals. FIG. 6 is an enlarged view of the periphery of the capstan 3b on the right side of FIG. 1, and shows the substrate 39 and the traveling direction switching plate 40 by imaginary lines. A pin B provided at one end of an oscillating plate 41 (an oscillating member as a pressing means) is rotatably attached to the traveling direction switching plate 40 in a support hole 40a. The rocking plate 41 is provided with a guide groove 41a (guide portion) into which a cylinder 42a (non-engaging portion) of a transmission gear 42 described later fits, and a pin C at the other end. The pin C is fitted in a groove 39a provided in the substrate 39 whose center passes through the rotation center of the transmission gear 42 in the direction orthogonal to the moving direction of the traveling direction switching plate 40.

The guide groove 41a is formed between the pin B and the pin C. When the transmission gear 42 rotates clockwise from the state of FIG. 6, the rocking plate 41 rotates counterclockwise about the pin C as the column 42a moves within the guide groove 41a. Then, the pin B at the turning tip moves the traveling direction switching plate 40 in the arrow G direction.

On the lower surface of the substrate 39, a flywheel 19 attached to the capstan 3b, a small gear 20 (driving gear) integrated with the flywheel 19, and a first toothless portion 21a of the small gear 20. The tooth-missing gear 21 facing the toothless gear 21 and the transmission gear 42 at a position facing the second toothless portion 21 b of the tooth-missing gear 21 are rotatably supported by the substrate 39. An endless belt for transmitting the rotation of the motor 2 is hung on the outer circumference of the flywheel 19, so that when the rotation direction of the motor 2 is switched, the rotation of the flywheel 19 is also switched according to the rotation direction of the motor. Has become. On the capstan 3b, a starting gear 23 having a diameter smaller than that of the small gear 20 is rotatably provided above the small gear 20 via a sliding rotation transmission mechanism. The tooth-missing gear 21 has a large-diameter gear 21c that constantly meshes with the starting gear 21 and toothed portions formed between the first and second tooth-missing portions 21a and 21b having a smaller diameter than the large-diameter gear 21c. 21d and a circular arc groove 21e into which a stopper 1c protruding from the bottom surface of the substrate is inserted are integrally formed. The circular arc angle of the circular arc groove 21e is such that when the first and second toothless portions 21a and 21b face the small gear 20, the stopper 1c abuts the terminal ends 21k and 21m of the circular arc groove.

The transmission gear 42 is provided with a columnar 42a that protrudes to the upper surface side of the substrate through the circular arc hole 39b opened in the substrate 39 when the transmission gear 42 is attached to the substrate. The arc angle of the arc hole 39b of the base plate 39 is set at a position where the transmission gear 42 meshes with the toothed portion of the tooth-missing gear and receives a rotation of the tooth-missing gear for half a rotation, or a position slightly less than a half rotation. The column 42a is sized to abut the ends 39c and 39d of the arc holes.

In FIG. 7, when the traveling direction switching plate 40 of FIG. 5 is at the end of the movement in the direction of arrow D, the reaction force of the accompanying direction switching plate 40 causes the force transmitted to the transmission gear 42 via the swing plate 41. Shown as a vector. The reaction force F of the traveling direction switching plate 40 acts on the pin B in the direction of arrow G to urge the swing plate 41 to rotate counterclockwise about the pin C. This rotation biasing force presses the column 42a fitted into the guide groove 41a with a force f in a direction orthogonal to the side 41b of the guide groove 41a. At this time, if the vector of the force f points to the left side of the line connecting the center o of the cylinder 42a and the center p of the transmission gear 42, the vector of the component force t of the force f becomes the center o of the cylinder 42a and the transmission gear 42. The column 42a faces the left side in FIG. 7 in the direction orthogonal to the line connecting the center p of 42.

As a result, the component force t acting on the column 42a tends to rotate the transmission gear 42 counterclockwise. However, as shown in FIG. 6, the column 42a comes into contact with the end 39d of the arc hole 39b of the substrate 39 and is prohibited from rotating counterclockwise. Therefore, the transmission gear 42 is held in a state in which it is urged counterclockwise by the reaction force of the traveling direction switching plate 40 in the rotation continuation direction. When the transmission gear 42 is held in a state in which it is biased in the rotation continuation direction, the traveling direction switching plate 40 is a reaction force acting on the traveling direction switching plate 40, so It is held at the moving end position.

In the third embodiment, the reaction force of the traveling direction switching plate 40 continues to urge the transmission gear 42 in the rotation continuation direction even if the transmission gear 42 has a rotation amount that is slightly less than a half rotation. By providing the means, the traveling direction switching plate 40 can be held at one or the other movement end position. In addition, in the third embodiment, the rocking plate 41 rotates, but the rotation range is within the range of the inner circumference of the tooth tip of the transmission gear 42 and is arranged so as to overlap the transmission gear 42. The moving plate 41 does not hinder the arrangement of other parts. Further, since the oscillating plate 41 is rotated by the rotational force of the transmission gear 42, a sufficient turning force is given.

Further, as described in the first embodiment, the pressing and urging means may be the inclined surface 18b formed in the guide hole 18 of the traveling direction switching plate 10.

[0041]

[Effect of device]

 The tape recorder auto-reverse device of the present invention has a traveling direction switching mechanism that switches the traveling direction of the tape by switching the rotational direction of the motor, a drive gear to which the rotation from the motor is transmitted, and a toothless gear of the motor. By engaging the starter gear whose rotation direction is changed by changing the rotation direction, and receiving the rotation of the toothless gear to rotate the transmission gear at least half a turn, the traveling direction changeover plate linked to the transmission gear is switched to one or the other. Since the tape is moved to switch the traveling direction of the tape, a member for reversing the traveling direction is not required, and the traveling direction switching device can be downsized and the operation can be stabilized.

[Brief description of drawings]

FIG. 1 is a plan view of a mechanism portion of a tape recorder showing a first embodiment of the present invention.

FIG. 2 is a partial plan view of the embodiment.

FIG. 3 is an exploded perspective view of the same embodiment.

FIG. 4 is a back view of the embodiment.

FIG. 5 is a partial plan view of the second embodiment.

FIG. 6 is a partial plan view of the third embodiment.

FIG. 7 is a plan view showing the working relationship of forces in the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1b, 1d Blocking section 2 Motor 3 Capstan 4 Pinch roller 8 Reel shaft 10 Traveling direction switching member 18 Engagement section 20 Drive gear 21 Partial tooth gear 21a First toothless section 21b Second toothless section 21d Yes Tooth portion 22 Transmission gear 22a Engaged portion 23 Starting gear 41 Pressing means

Claims (6)

[Scope of utility model registration request] 1. A pinch roller switching mechanism that selectively presses a pair of pinch rollers (4a, 4b) against corresponding capstans (3a, 3b), and a motor (2) that rotates forward and backward and a reel shaft (8a). , 8b)
And a traveling direction switching member (10) for switching the pinch roller switching mechanism by the rotational force of a drive gear (20) rotated by the motor, A holding mechanism for holding the direction switching member (10) at a position moved to one side or the other side against the reaction force of each mechanism, and first and second toothless portions (21a, 21b), A toothed portion (21d) formed between the first and second toothless portions
A toothless gear (21) that engages with the drive gear to rotate forward and backward, and when the drive gear faces the first and second toothless portions, the rotation of the drive gear in the rotation continuing direction is prohibited.
And a starting gear (23) for rotating the tooth-missing gear in the forward or reverse rotation direction by transmitting a rotational force from the motor through a sliding rotation transmission mechanism, and an engaging portion (18) of the traveling direction switching member. A transmission gear that has an engaged portion that engages with the toothless gear, engages with the toothed portion of the toothless gear and makes a substantially half rotation, and moves the traveling direction switching member to one side or the other according to the rotation direction. (22)
And a block for inhibiting the rotation of the transmission gear in the rotation continuation direction by the toothed portion by contacting the contact portion of the transmission gear when the transmission gear faces the first or second toothless portion. Part (1b,
1d) is provided, and an auto-reverse device for a tape recorder. 2. The non-engagement portion by the reaction force acting on the traveling direction switching member at the position where the traveling direction switching member is moved to one side or the other, wherein the contact portion is the engaged portion (21a). 2. The automatic reverse device for a tape recorder according to claim 1, wherein an inclined surface (18b) for pressing the block against the blocking portion is formed in the engaging portion. 3. An elastic member for biasing the transmission gear (22) in the same direction as the rotation direction of the toothless gear at the position where the contact portion abuts against the blocking portion. 24)
The automatic reverse device for a tape recorder according to claim 1, further comprising: 4. A pinch roller switching mechanism that selectively presses a pair of pinch rollers (4a, 4b) against corresponding capstans (3a, 3b), and a motor (2) that rotates forward and backward and a reel shaft (8a). , 8b)
And a traveling direction switching member (10) for switching the pinch roller switching mechanism by the rotational force of a drive gear (20) rotated by the motor, A holding mechanism for holding the direction switching member (10) at a position moved to one side or the other side against the reaction force of each mechanism, and first and second toothless portions (21a, 21b), A toothed portion (21d) formed between the first and second toothless portions
A toothless gear (21) that engages with the drive gear to rotate forward and backward, and when the drive gear faces the first and second toothless portions, the rotation of the drive gear in the rotation continuing direction is prohibited.
A starting gear (23) for rotating the toothless gear in a forward or reverse rotation direction by transmitting a rotational force from the motor through a sliding rotation transmission mechanism; and an engaged portion (24a) at an eccentric position. Then, it meshes with the partially toothed gear that rotates in the normal and reverse directions and makes a substantially half rotation, and transmits the circular arc motion of the engaged portion to the engaging portion of the traveling direction switching member so that the traveling direction switching member is moved to one side or the other side. When the traveling direction switching member is not driven, the transmission gear (4) arranged to face the toothless portion of the toothless gear.
2) and, at least immediately before the toothed portion of the tooth-missing gear is disengaged from the transmission gear, a pressing means for continuously urging the transmission gear in the rotation continuation direction by the reaction force acting on the traveling direction switching member. An auto-reverse device for tape recorders. 5. The pressing means has one end (B) rotatably mounted on a part of the traveling direction switching member and the other end (C) in a direction orthogonal to the moving direction of the traveling direction switching member. A rocking member (41) which is on the rotation center line of the transmission gear and has a guide portion (41a) between both ends which is fitted to the engaged portion of the transmission gear and biases the transmission gear in the rotation continuation direction. The automatic reverse device for a tape recorder according to claim 4, wherein 6. The pressing means applies to the engaging portion (18) for pressing the engaged portion at one or the other rotation end position of the transmission gear to urge the transmission gear in the rotation continuation direction. 5. The tape recorder auto-reverse device according to claim 4, wherein the inclined surface (18b) is formed.